/*
 * Added the following header as some of the source in this class
 * has been derived from material (and example classes) in the Java
 * Tutorial.
 * 
 * Copyright 2001-2002 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or 
 * without modification, are permitted provided that the following 
 * conditions are met:
 * 
 * -Redistributions of source code must retain the above copyright  
 * notice, this  list of conditions and the following disclaimer.
 * 
 * -Redistribution in binary form must reproduct the above copyright 
 * notice, this list of conditions and the following disclaimer in 
 * the documentation and/or other materials provided with the 
 * distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY 
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY 
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 */

package org.ds.auth;

import java.io.IOException;
import java.util.Map;

import javax.security.auth.Subject;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;
import javax.security.auth.login.LoginException;
import javax.security.auth.spi.LoginModule;

/**
 * This class implements a customized authentication mechanism by implementing
 * the LoginModule interface.
 * 
 * @author Kartick Suriamoorthy
 */
public class DSLoginModule implements LoginModule
{
	// handle to the callback handler.
	CallbackHandler handler = null;

	public boolean abort() throws LoginException
	{
		// TODO kartick : need to implement abort.
		System.out.println("Inside abort ...");

		return false;
	}

	public boolean commit() throws LoginException
	{
		// TODO kartick : need to implement commit
		System.out.println("Inside commit ...");

		return true;
	}

	public void initialize(Subject subject, CallbackHandler handler, Map<String, ?> sharedState, Map<String, ?> options)
	{
		// get a handle to the callback handler
		this.handler = handler;
	}

	public boolean login() throws LoginException
	{
		System.out.println("Inside login ...");

		// create Callback instances to the get the username and password
		Callback[] callbacks = new Callback[2];
		callbacks[0] = new NameCallback("Username");
		callbacks[1] = new PasswordCallback("Password", false);

		try
		{
			// call the callback handler - this is the step where the username
			// and
			// password are acquired and set in their respective callback
			// instances.
			handler.handle(callbacks);
		}
		catch (IOException ioe)
		{
			throw new LoginException("Error during authentication. Error Message : " + ioe.getMessage());
		}
		catch (UnsupportedCallbackException uce)
		{
			throw new LoginException("Unsupported Callback : " + uce.getCallback().toString());
		}

		String username = ((NameCallback) callbacks[0]).getName();
		char[] password = ((PasswordCallback) callbacks[1]).getPassword();

		// validate the user
		boolean validated = UserDictionary.getInstance().validateUser(username, password);

		return validated;
	}

	public boolean logout() throws LoginException
	{
		System.out.println("Inside logout ...");

		return false;
	}
}